Method for manufacturing a semiconductor device

Abstract

The present invention relates to a method for manufacturing a semiconductor device including a method for reforming an insulating film formed by a low temperature CVD method. It is an object of the present Invention to provide a method for manufacturing a semiconductor device capable of improving a film quality of an insulating film formed by a CVD method which is able to form a film at a low temperature and also capable of maintaining mass productivity, in which processing by irradiation with ultraviolet rays of the insulating film while heating the film after forming an insulating film (4) on a body to be formed by a chemical vapor deposition method is included.

What is claimed is: 
     
       1. A method for forming an insulating film comprising the steps of: a) forming an insulating film on a substrate by chemical vapor deposition, said insulating film being formed of a material selected from the group consisting of SiO 2 , PSG, BSG and BPSG;   b) heating said substrate to an elevated temperature of 200°-240° C.;   (c) thereafter irradiating said insulating film with ultraviolet rays while maintaining said substrate at said elevated temperature to densify said film over its entire thickness.   
     
     
       2. A method for forming an insulating film according to claim 1, wherein said film on said substrate is SiO 2  formed by CVD from a reaction gas which is a gas mixture of mono-silane (SiH 4 ) and oxygen (O 2 ). 
     
     
       3. A method for forming an insulating film according to claim 1, wherein the film on said substrate is one of PSG, BSG and BPSG formed from a reaction gas which is a gas mixture of mono-silane (SiH 4 ), oxygen (O 2 ) and a gas containing at least one of phosphorous (P) and boron (B). 
     
     
       4. A method for forming an insulating film according to claim 1, wherein said film on said substrate is SiO 2  formed by CVD from a reaction gas which is a gas mixture containing an organic silane and ozone (O 3 ). 
     
     
       5. A method for forming an insulating film according to claim 4, wherein said organic silane is an alkoxy-containing compound of silicon, siloxane or alkyl silane. 
     
     
       6. A method for forming an insulating film according to claim 1, wherein the film on said substrate is any of PSG, BSG and BPSG formed from a reaction gas which is a gas mixture of an organic silane, ozone (O 3 ) and a gas containing at least one of phosphorous (P) and boron (B). 
     
     
       7. A method for forming an insulating film according to claim 6, wherein said organic silane is an alkoxy-containing compound of silicon, a siloxane or an alkyl silane. 
     
     
       8. A method for forming an insulating film according to claim 1, wherein the insulating film is provided with a greater thickness than first deposited thickness by repeating steps (a), (b), (c) and (d) a plurality of times. 
     
     
       9. A method for forming an insulating film comprising the steps of: a) forming an insulating film on a substrate by chemical vapor deposition, said insulating film being formed of a material selected from the group consisting of SiO 2 , PSG, BSG And BPSG;   b) heating said substrate to an elevated temperature of 200°-450° C.;   c) contacting said film with ammonia gas; and   d) thereafter irradiating said insulating film with ultraviolet rays while maintaining said substrate at said elevated temperature and said film in contact with said ammonia gas, to densify said film over its entire thickness.   
     
     
       10. A method for forming an insulating film according to claim 9, wherein said elevated temperature of said substrate is 350° C. to 450° C. while said insulating film is irradiated with ultraviolet rays. 
     
     
       11. A method for forming an insulating film according to claim 9, wherein said film on said substrate is SiO 2  formed by CVD from a reaction gas which is a gas mixture of mono-silane (SiH 4 ) and oxygen (O 2 ). 
     
     
       12. A method for forming an insulating film according claim 9 wherein the film on said substrate is one of BSG and BPSG formed from a reaction gas which is a gas mixture of mono-silane (SiH 4 ), oxygen (O 2 ) and a gas containing at least one of phosphorous (P) and boron (B). 
     
     
       13. A method for forming an insulating film according to claim 9 wherein said film on said substrate is SiO 2  formed by CVD from a reaction gas which is a gas mixture containing an organic silane and ozone (O 3 ). 
     
     
       14. A method for forming an insulating film according to claim 12, wherein said organic silane is an alkoxy-containing compound of silicon, a siloxane, or an alkyl silane. 
     
     
       15. A method for forming an insulating film according to claim 9, wherein the film on said substrate is one of PSG, BSG and BPSG formed from a reaction gas which is a gas mixture containing an organic silane and ozone (O 3 ), and a gas containing at least one of phosphorous (P) and boron (B). 
     
     
       16. A method for forming an insulating film according to claim 15, wherein said organic silane is an alkoxy-containing compound of silicon, a siloxane or an alkyl silane. 
     
     
       17. A method for forming an insulating film according to claim 9, wherein the insulating film is provided with a greater thickness than first deposited thickness by repeating steps (a), (b), (c) and (d) a plurality of times. 
     
     
       18. A method for forming an insulating film according to claim 1 wherein said elevated temperature is 300°14 450° C. 
     
     
       19. A method for forming an insulating film according to claim 9 wherein said elevated temperature is 300°-450° C.